1. Field of the Invention
The present invention relates to a linear compressor, and in particular to a linear compressor which is capable of improving efficiency of the compressor by minimizing flow channel resistance generated in a reciprocating motion of a piston.
2. Description of the Prior Art
In general, in a linear compressor compressing fluid such as air or coolant gas, linear driving force of a motor is transmitted to a piston, and the piston sucks and compresses the coolant gas by performing a linear reciprocating motion.
Hereinafter, the conventional linear compressor will now be described.
As depicted in FIG.1xcx9cFIG.3, the conventional linear compressor comprises a casing V having a certain amount of oil at the inner bottom surface, a compression unit C installed horizontally inside of the casing V for compressing and discharging the coolant after sucking, and an oil feeder O fixed on the external of the compression unit C for providing oil to a sliding portion.
The compression unit C comprises a frame 1 having a ring shape, a cover 2 fixedly installed on the side of the frame 1, a cylinder 3 fixed horizontally on the center of the frame 1, an inner stator assembly 4a fixed on the. outer circumference of the frame 1 supporting the cylinder 3, an outer stator assembly 4b fixed on the outer circumference of the inner stator assembly 4a with a certain void, a magnet assembly 5 interposed on the void between the inner and outer stator assembly 4a, 4b, a piston 6 connected to the magnet assembly 5 for sucking and compressing the coolant gas by performing a sliding motion inside of the cylinder 3, an inner and outer resonance spring 7a, 7b for inducing the magnet assembly 5 to perform a resonance motion continually at the void between the inner and outer stator assembly 4a, 4b, and a discharge valve assembly 8 installed on the front end of the cylinder 3 for controlling discharge of a compressed gas in the reciprocating motion of the piston 6.
The piston 6 includes a body portion 6a having a certain length, a head portion 6b having a disk flange shape connected to the magnet assembly 5 formed on the rear portion of the body portion 6a, and a gas flow channel F formed on the center of the body portion 6a for guiding the coolant gas to the cylinder 3.
A curved portion 5a is formed on the magnet assembly 5 having a disk shape in order to be connected to the head portion of the piston 6.
A non-described reference numeral 9 is a suction valve, SP is a suction pipe, and a VP is a discharge pipe.
The operation of the conventional linear compressor will now be described.
Current is applied to the inner and outer stator assembly 4a, 4b, the magnet assembly 5 performs the linear reciprocating motion, the piston 6 connected to the magnet assembly 5 performs the reciprocating motion linearly inside of the cylinder 3, pressure difference occurs inside of the cylinder 3, the coolant gas inside of the casing V is sucked into the cylinder 3 through the gas flow channel F of the piston 6 by the pressure difference inside of the cylinder 3, is compressed, and is discharged. The above-described operation is performed repeatedly.
Herein, part of the coolant gas sucked in the suction process of the piston 6 through the suction pipe SP flows to inner side of the cover 2 in the reciprocating motion of the piston 6, the part of the coolant gas flows again inside of the magnet assembly 5 through the void of the inner and outer stator assembly 4a, 4b, accordingly the coolant is evenly distributed all over the casing V.
However, in the conventional linear compressor, the coolant gas fills generally the connection portion of the magnet assembly 5 and piston 6, namely, the curved portion 5a of the magnet assembly 5 and head portion 6a of the piston 6, however the connection portion of the magnet assembly 5 and piston 6 seems to be blocked, accordingly flow resistance of the fluid occurs in the reciprocating motion of the piston and the efficiency of the compressor lowers.
It is an object of the present invention to provide a linear compressor which is capable of minimizing a flow resistance of fluid occurred in a reciprocating motion of the piston.
To achieve the object, a linear compressor of the present invention including a casing filled with oil at the bottom surface having a suction pipe and a discharge pipe, a unit elastically supported so as to be horizontally excited minutely inside of the casing including a cylinder formed on the inner center, an oil feeder installed on the bottom surface of the unit sunk under the oil for providing oil to the unit, an inner and outer stator assembly installed on the external of the cylinder so as to have a certain void between each other, a magnet assembly inserted into the certain void of the inner and outer stator assembly for performing a reciprocating motion linearly, a piston connected to the magnet assembly for performing the linear reciprocating motion inside of the cylinder in accordance with the linear reciprocating motion of the magnet assembly, an inner and outer resonance spring installed between the cylinder and unit for inducing the magnet assembly to perform a resonance motion continually between the inner and outer stator assembly, and a discharge valve assembly combined to the front end of the cylinder and connected to a discharge pipe of the casing for controlling discharge of the compressed gas in the reciprocating motion of the piston, comprises a gas through hole formed on the connection portion of the magnet assembly and piston formed so as to be square with the direction of the reciprocating motion of the magnet assembly and piston in order to decrease the flow resistance due to the coolant gas occurred in the reciprocating motion of the magnet assembly and piston.
In addition, in the linear compressor of the present invention, a gas through hole is formed on the side wall surface of the magnet assembly in order to decrease the flow resistance occurred in the reciprocating motion of the piston due to the coolant gas.
In addition, in the linear compressor of the present invention, a plurality of gas through holes having a ring shape are formed and are zigzag-arrayed along the outer circumference of the sidewall of the magnet assembly.